Google Research: Cardiometabolic Risk from Smartphone Photos (PhotoScan)
A health-AI piece with a clever engineering core. Jordan and Riley cover PhotoScan, a deep-learning framework that estimates 3D body-composition metrics — body fat %, android-to-gynoid (apple vs. pear) fat ratio, and visceral-to-subcutaneous fat ratio — from ordinary 2D smartphone photos, to flag insulin resistance (which precedes type 2 diabetes by years and is poorly captured by BMI). The standout trick solves a data problem: pre-train a ResNet-50 (ImageNet-init) on UK Biobank (N=35,323) using 2D projections rendered from 3D MRI with DXA as ground truth, fuse image features with sex/height/weight/BMI, and output probability density functions (uncertainty, not point guesses); then fine-tune on real smartphone photos (PhotoBIA, N=677, with landmark detection picking best frames from 360-degree video) and validate on an independent cohort (N=132), hitting near-DXA agreement and beating smartwatch impedance sensors — while unlocking ratios impedance can't measure. Transferable lessons: bootstrap a cheap deployment modality from a data-rich hard-to-collect one via projection; fuse image + tabular; predict distributions when stakes are clinical. Caveat: investigational, not a cleared medical device. Source: Seeing beyond BMI: Estimating cardiometabolic risk with smartphone imagery — Google Research Blog, Aug 17 2026 (paper: arXiv:2603.27017) — https://research.google/blog/seeing-beyond-bmi-estimating-cardiometabolic-risk-with-smartphone-imagery/ This is commentary/summary in the hosts' own words, not a reproduction of the article.